Up to now, an ejector-type refrigeration cycle that is a vapor compression refrigeration cycle device having an ejector as a refrigerant depressurizing device has been known.
In the ejector-type refrigeration cycle of this type, a refrigerant that has flowed out of an evaporator is drawn into a refrigerant suction port of the ejector by a suction action of an ejection refrigerant ejected at high speed from a nozzle portion of the ejector. A mixture refrigerant of the ejection refrigerant and the drawn refrigerant is increased in pressure by a diffuser portion (pressure increase portion) of the ejector, and then drawn into a compressor.
With the above configuration, in the ejector-type refrigeration cycle, a pressure of the drawn refrigerant can be increased more than the pressure of the drawn refrigerant in a normal refrigeration cycle device in which a refrigerant evaporation pressure in an evaporator is substantially equal to a pressure of the drawn refrigerant to be drawn into the compressor. Therefore, in the ejector-type refrigeration cycle, a coefficient of performance (COP) of the cycle can be improved with a reduction of a power consumption of the compressor.
Further, Patent Document 1 discloses an ejector (hereinafter referred to as “ejector module”) integrated with a gas-liquid separation device (gas-liquid separation portion).
According to the ejector module of Patent Document 1, a suction side of the compressor is connected to a gas-phase refrigerant outflow port, out of which a gas-phase refrigerant separated by the gas-liquid separation device flows. A refrigerant inflow port side of the evaporator is connected to a liquid-phase refrigerant outflow port, out of which a liquid-phase refrigerant separated by the gas-liquid separation device flows. Further, a refrigerant outflow port side of the evaporator is connected to the refrigerant suction port, thereby being capable of extremely easily configuring the ejector-type refrigeration cycle.
However, in the ejector module of Patent Document 1, since the gas-liquid separation device has an integrated configuration, the liquid-phase refrigerant separated by the gas-liquid separation device is likely to absorb a heat from the external when the ejector module per se or an inlet pipe connecting a liquid-phase refrigerant outflow port of the ejector module and a refrigerant inflow port of the evaporator is placed under a high-temperature environment.
Then, when the liquid-phase refrigerant separated by the gas-liquid separation device absorbs heat from the external, and an enthalpy of the refrigerant flowing into the evaporator rises, a refrigeration performance delivered in the evaporator may decrease. Incidentally, the refrigeration performance delivered in the evaporator is defined by an enthalpy difference obtained by subtracting an enthalpy of the refrigerant on an evaporator inlet side from an enthalpy of the refrigerant on an evaporator outlet side.
Further, in the ejector-type refrigeration cycle, a temperature of the refrigerant flowing into the evaporator becomes lower than that in a general refrigeration cycle device. For that reason, as compared to the general refrigeration cycle device, a temperature difference between the refrigerant flowing into the evaporator and the external is likely to be large, and the enthalpy of the refrigerant flowing into the evaporator is likely to increase.